Phosphodiesterase inhibitors Flashcards
What role does phosphodiesterase play in cell signalling
PDE degrades cAMP/cGMP which causes a decrease in cell signalling
By inhibiting PDE, PDE inhibitors effect cell signaling how
by increasing the levels of the second messengers cAMP/cGMP
Name the classification of PDE inhibitors
Non-selective PDE inhibitors
PDE 1 Inhibitors
PDE 3 Inhibitors
PDE5 Inhibitors
Name a major family of non-selective PDE inhibitors
methylxanthines
Methylxanthines work by what two mechanisms
inhibits PDE
adenosine antagonist (A1/A2) receptors
*not alpha
Name four methylxanthines (nonselective PDEI)
Caffeine
Pentoxifylline
Papaverine
Theophylline
What are the two clinical uses of caffeine
treats PDPH
treats apnea of prematurity
What is pentoxifylline used to tx
PVD
*alters the rheology (flow) of RBCs
What is papaverine used for
spasmolytic producing vasodilation, GI sphincter, bronchiolar smooth muscle relaxation
relieves peripheral, myocardial and cerebral ischemia
*used in OR to prevent arterial vasospasm
What are the two actions of theophylline
smooth muscle relaxation»bronchodilation
adenosine antagonist»>cardiac stimulation
Name a PDE 1 inhibitor
Vinopectine
What is the MOA of vinopectine
inhibits calmodulin-stimulated PD
- leads to an increase in cGMP»vasodilation of cerebral smooth muscles
- increases CPP»increase memory and neuroprotection
Name five PDE 3 inhibitors
M.E.A.L.C milrinone enoximone amrinone levosimendan cilostazol
What is Amrinones and Milrinone’s action on the heart and vascular smooth muscle
Positive inotropic
Vasodilation»decreased SVR, PVR, PAOP, MAP
Amrinone and Milrinone are indicated for
CHF
